The present invention relates generally to bearing seals and more particularly to a turbine engine bearing seal with a backup device.
Segmented circumferential or a carbon ring seals are sometimes used to contain oil in the bearing compartments of a gas turbine engine or other mechanical device. A pair of axially-spaced seals are provided between the oil and the air in the housing, an oil-side seal and an air-side seal. In order to provide proper operation of the seals, air at an elevated pressure is introduced between the seals. This elevated air pressure urges the seals axially apart from one another and radially inward to improve the seal.
In the event of failure of either of the seals, the elevated air pressure is lost, thereby significantly reducing the effectiveness of the seal. This can result in the escape of oil from the oil compartment. Even a slight failure of one of the seals can cause a loss of air pressure, which in turn can result in a loss of oil from the oil compartment.